Research in animals is critical for investigating basic cancer biology, as well as development of diagnostic and therapeutic modalities for human cancer. Thus, the major goal of the program in Cancer Biology in Animals is to utilize key strengths at UC Davis in animal research on disease mechanisms relevant to cancer. The Davis campus excels in the availability of a large number of diverse animal models, high levels of veterinary expertise, and superb facilities for care and housing of many species. Also, this program will promote collaborative efforts among investigators on the Davis campus, the Medical Center in Sacramento, and Lawrence-Livermore National Labs for preclinical research, i.e., bridging tumorigenesis research in the animal model research with the human clinical setting. Leadership for this Program is provided by Drs. Paul Luciw and Robert Cardiff, who are senior investigators in the new Center for Comparative Medicine on the UC Davis campus. Both have extensive research experience on tumorigenic retroviruses; Dr. Luciw's expertise in molecular virology is complemented by Dr. Cardiff's expertise in pathology and cancer biology. Collectively, both Program leaders direct multidisciplinary basic research programs that involve collaborators and resources at the Center for Comparative Medicine, the California Regional Primate Research Center, and the new UCD Mouse Biology Program. Research activities on cancer in the Program in Cancer Biology in Animals are organized into three investigational themes: 1) Tumor Biology and Mechanisms of Carcinogenesis: 2) Infectious Agents and Cancer in Animal Models; 3) Preclinical Assessment of Novel Anti- Cancer Therapeutics; 2) Infectious Agents and Cancer in Animal Models; 3) Preclinical Assessment of Noel Anti-Cancer Therapeutics and Diagnostics. In addition, this program encompasses a critical resource theme-the Mouse Biology Program. Many individual research activities within each of these themes are highly interactive with activities in the other Programs (i.e., Molecular Oncology, Clinical Therapeutics, Prostate Cancer, Biomedical Technology, and Cancer Control).